[Memory T cell subsets in peripheral blood of patients with multiple sclerosis].

OBJECTIVE: To investigate the phenotypes of memory T cell subsets in the patients with multiple sclerosis (MS) and further explore the mechanisms that lead to the changes of the memory T cell subsets. METHODS: Peripheral blood samples were collected from 20 MS patients, 9 with relapsing-remitting MS (RRMS) and 11 with secondary progressive multiple sclerosis (SPMS), 20 patients with cerebral infarction (disease control group), and 22 healthy persons (healthy control group). Flow cytometry and ELISA were used to detect the phenotypes of the memory T cell subsets and plasma concentration of interleukin-15 (IL-15). RESULTS: The level of CD8+ TCM of the MS group was 20% +/- 11%%, significantly higher than that of the healthy control group (13% +/- 6%, P < 0.05). The level of the CD8+ terminal effector memory T cells of the MS group was 24% +/- 15%, significantly lower than that of the healthy control group (39% +/- 19%, P < 0.05). The plasma IL-15 level of the MS group was 36.01 pg/m, significantly higher than that of the healthy control group (9.53 pg/ml, P < 0.05). CONCLUSION: The upregulation of CD8+ TCM in the MS patients may reflect a persistent chronic inflammatory response that may have been induced during early stages of the disease, while IL-15 may participate in the immunoregulatory process of promoting TCM differentiation.